An Ultra High Definition (UHD) broadcast may provide a service differentiated from an existing broadcast and provide a high sense of presence of a high level, by representing luminance that has not been expressed in conventional content. However, research into High Dynamic Range (HDR) video is underway and development of a method for acquiring an HDR image and a display device capable of displaying the HDR image is still in progress. Therefore, a method is needed in which a legacy receiver having difficulty in expressing an HDR is capable of representing content with the HDR image even in an environment in which the HDR image is provided. Currently, as a method for considering backward compatibility in an environment having a limited transmission bandwidth, a scalable approach scheme is being used and a study is needed to enable configuration and display of a dynamic rage image suitable for the capability of each receiver, using the scalable approach scheme.
In the UHD broadcast, there has been discussion focusing on providing realistic content to viewers in various aspects in order to provide a broadcast service differentiated from an existing High Definition (HD) broadcast. Thereamong, the necessity for an HDR has been stressed to cause a luminance expression range of content to approximate to a human visual system. However, when content with the HDR is obtained and transmitted, the case may occur in which a legacy display does not properly present the content or cannot display the content at all. In a situation in which a study about the HDR and discussion about specification related to the HDR are being conducted, an HDR display will be supplied and a technique for providing an HDR broadcast service considering backward compatibility with a legacy display is needed.
Meanwhile, in a situation in which content and display having an HDR are introduced to a broadcast, it is necessary to supply proper content according to the luminance expression range of a consumer display. That is, content suitable for a dynamic range characteristic of each of a display having an existing Low Dynamic Range (LDR) and a display having an HDR needs to be supplied. However, provision of the same content with different dynamic ranges in a situation in which bandwidth for a broadcast service is limited has a problem of using double an existing bandwidth.